Effects of genetic selection for growth on frost hardiness in western hemlock

摘要: Fall and spring frost hardiness was determined from electrolytic leakage of artificially frozen needle segments in 22 full-sib families western hemlock (Tsuga heterophylla (Raf.) Sarg.) British Columbia Washington State representing different levels genetic gain, four provenance materials (stand progenies the Queen Charlotte Islands, Vancouver Island, Oregon Cascades, seed-orchard northern Coast Range). Samples for freeze testing were collected a 5-year-old trial at Jordan River on southwestern Island. Height date bud flush recorded field. Genetic gain among not correlated with fall hardiness, but high-yielding displayed lower an earlier than low-yielding families. Both increased height growth decreased latitude provenances. The highest growth, earliest lowest sprin...